Along with the remarkable development of broadband techniques such as x Digital Subscriber Line (xDSL), there were over 15 million broadband network users in China in 2003. At present, conventional broadband networks are primarily used for bearing data services. Video services are basically virgin ground in the conventional broadband networks. However, the video services will become a new kind of services principal for telecommunication operators to attract broadband users. The technologies of the video service are now being updated and developed, and some of the key technologies of the broadband video service are user authentication and authority control.
Currently, the broadband video service has such modes as Video on Demand (VoD), Near Video On Demand (NVOD), and Internet Group Management Protocol (IGMP), and multimedia flow is transferred in a multicast form. At present, the multicast is mostly controlled based on protocols, which makes it difficult to flexibly control the authority of multicast users, thus limiting the development of the broadband video service.